Braidless guide catheter

ABSTRACT

Guide catheter incorporating a braidless construction having increased performance characteristics for catheterization procedures. The guide catheter may include a tracking wire, inner or outer guide for positioning the guide catheter within the patient&#39;s vascular system.

This application is a continuation of application Ser. No. 08/909,756,now U.S. Pat. No. 6,185,449 filed Aug. 12, 1997, which is a continuationof application Ser. No. 08/398,214, filed on Mar. 2, 1995, now U.S. Pat.No. 5,680,873.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to guide catheters and diagnosticcatheters used in medical catheterization procedures. In particular, thepresent invention relates to an improved guide or diagnostic catheterhaving a simple, braid-free catheter design, which is capable ofperforming the functions of conventional diagnostic and guide catheters.

2. Description of the Prior Art

Guide catheters and diagnostic catheters are well known for use incoronary catheterization and percutaneous transluminal coronaryangioplasty (PTCA) procedures. Guide catheters aid in treatment ofarterial lesions by providing a conduit for positioning dilatationballoon systems across an arterial stenosis. Guide catheters anddiagnostic catheters work with various assemblies for performing othermedical, therapeutic, and diagnostic procedures, such as dye delivery,arterial flushing, or arterial pressure monitoring.

Diagnostic catheters are used during cardiac catheterization fordiagnosis of coronary artery disease in order to define vessel anatomy,isolate lesions, and identify adjacent cardiac branches which mayimpinge on the lesion and affect ventricular function.

For diagnosis of the coronary artery, the femoral artery is enteredpercutaneously and a sheath is inserted into the artery to provideaccess to the patient's vascular system. The diagnostic catheter isinserted into the femoral artery through this introducer sheath over aguide wire and advanced up the aorta to the aortic arch. Once over theaortic arch, the guide wire may be removed. A Y-adapter and manifoldassembly are attached to the diagnostic catheter for implementation ofdiagnostic procedures, such as dye delivery, flushing capabilities, andarterial pressure monitoring.

The diagnostic catheter design generally includes a shaft having aproximal and a distal end. A lumen extends longitudinally through theshaft from the proximal to the distal end. Operably connected to theproximal end of the shaft is a hub assembly, for connection tocatheterization equipment, and connected to the distal end of the shaftis a soft tip.

The distal end of the guide catheter shaft is shaped to access theostium of the coronary artery having the stenotic lesion. Differentshapes may be employed for access to the ostium of a right or leftcoronary artery, mammary artery or the ostium of a bi-pass vein. Duringthe diagnosis procedure, the physician advances and maneuvers thediagnostic catheter shaft within the artery, while at the same timeinjecting dye. The physician observes the dye using an angiographymonitor for visualization of the patient's coronary system.

The diagnostic catheter is advanced and maneuvered until the distal endis properly engaged in the ostium of the coronary artery the physicianbelieves to contain the stenosis. Once seated in the ostium, thephysician injects additional dye for observations of obstruction to dyeflow, indicative of the coronary disease.

For treatment of the coronary disease through angioplasty or othercatheter based treatments, guide catheters are used. The guide cathetersprovide access to the area within the arterial system containing thestenotic lesion, and support for the treatment catheter which oftenincludes a balloon dilatation system. Guide catheters similar inconstruction to diagnostic catheters, although they are generally largerin size. Prior art guide catheters typically have a pre-shaped distalsection or tip region to aid in access to the ostium of the coronaryartery to receive treatment.

In operation, the guide catheter is introduced over a guide wire througha previously placed femoral introducer sheath and advanced up to theaortic arch. The guide wire can then be removed, and the guide cathetercan be advanced and maneuvered until the guide catheter soft tip isproperly engaged in the ostium of the coronary artery to be dilatated. AY-adapter and manifold assembly are attached to the guide catheter hubat the proximal end for implementation of therapeutic procedures, suchas dye delivery, flushing capabilities, pressure monitoring and deliveryof the dilatation balloon system.

Diagnostic catheters and guide catheters are manufactured in hundreds ofshapes and curve styles to accommodate anatomical variances in humansand to access specific areas within the coronary system. Curve shapesare also designed to provide support against the aortic wall when seatedwithin the ostium, to resist the tendency for a catheter to “pop out” ofthe ostium (termed backout force) when injecting dye or advancing atreatment catheter into the artery. Catheters are presently specificallymanufactured with high curve retention to maintain catheter placementwithin the ostium and to resist backout forces.

During angioplasty procedures, the catheters must be able to traversetortuous pathways through blood vessels to the stenosis in a manner asatraumatic as possible. Therefore, to limit insertion time anddiscomfort to the patient, the catheter must be stiff enough to resistthe formation of kinks, while at the same time the catheter must possessflexibility to be responsive to maneuvering forces when guiding thecatheter through the vascular system. It is important that the guidecatheter exhibit good torque control such that manipulation of aproximal portion of the guide catheter is responsively translated to thetip or distal end of the catheter to curve and guide the catheterthrough the tortuous pathways.

To meet the above performance requirements, guide catheters anddiagnostic catheters are manufactured using polymers in conjunction witha braid of high-strength fibers or stainless steel wires incorporatedinto the tube. The guide catheters are generally formed of three layers:a first inner layer commonly formed of polytetrafluoroethylene todecrease the coefficient of friction between a balloon catheter and theguide catheter; a middle layer consisting of braided wire for torquecontrol; and a third, outer layer commonly formed of polyethylene,polyurethane, polyether blocked amide (PEBA) or a nylon-blend for stablepositioning of the guide catheter, and providing backout support duringother treatment procedures.

During diagnostic and therapeutic procedures, it is often necessary touse more than one shaped or curved catheter to access the rightcoronary, left coronary, mammary artery, or bipass vein forvisualization of each vessel. The procedure of exchanging diagnosticcatheters for visualization of different vessels requires moreprocedural time and exposes the patient to extended x-ray time andfluoroscopy. Additionally, hospitals are required to inventory hundredsof catheters with various curves, tip shapes and diameters toaccommodate the various procedures for each patient.

It is desirable in catheter design for the inside diameter of thediagnostic or guide catheter to be maximized relative to the outsidediameter, providing maximum space for dye flow and dilatation catheterdelivery. While designing catheters to meet these design goals, thecatheters must continue to meet performance requirements of burstpressure requirements, kink resistance, curve retention, columnstrength, and torque control for advancement within the patient'svascular system.

SUMMARY OF THE INVENTION

The present invention relates to an improved guide or diagnosticcatheter having a simple braid-free catheter design, capable ofperforming the function of conventional diagnostic and guide catheters.

In a preferred embodiment, the catheter of the present invention is foruse as a guide or diagnostic catheter in catheter procedures. Thecatheter includes a generally elongate shaft formed of a singlepolymeric layer having a proximal end and a distal end. A lumen extendslongitudinally between the proximal end and the distal end. Means areincluded within the lumen of sufficient diameter for supporting theshaft during the catheter placement. The means for supporting the shaftmay include a core wire having a non-metallic coating. The means forsupporting the shaft may be curved, or alternatively, the shaft may becurved.

The means for supporting the shaft may alternately include a secondshaft for insertion into the lumen during the catheter procedure. Thesecond shaft may include an elongate tubular member also having a lumenextending longitudinally therethrough. The catheter assembly may includemeans for securing the proximal end of the shaft to the proximal end ofthe second shaft. In an alternative embodiment, the means for supportingthe shaft is positioned over the shaft.

The present invention further includes a method of supporting a guide ordiagnostic catheter for positioning the catheter within a patient'svascular system. An elongate shaft formed of a single layer of polymericmaterial is provided which is inserted within the patient's vascularsystem. An elongate tubular member formed of a polymeric material isadvanced over the shaft, the shaft being of sufficient diameter fortransmitting forces between the tubular member and the shaft. A distalend of the tubular member is positioned within the patient's vascularsystem. The shaft may include a core having a polymeric coating. Thedistal end of the shaft may be positioned within the ostium of thecoronary to receive treatment.

Alternatively, the shaft may include a second tubular member formed of apolymeric material. The proximal end of the second tubular member may belocked to the proximal end of the shaft. The distal end of the secondtubular member may be engaged in the ostium of a coronary within thevascular system.

Alternatively, the distal end of the first tubular member may extendbeyond the distal end of the second tubular member, and the distal endof the first tubular member is engaged within the ostium of a coronarywithin the vascular system. The second tubular member is advanced,tracking over the first tubular member until the distal end of thesecond tubular member is engaged in the ostium. The first tubular memberis removed from the patient's vascular system. Alternatively, the secondtubular member may be removed from the patient's vascular system.

The present invention provides an economically feasible diagnostic orguide catheter design which may be universally usable for mostanatomical situations. The catheter of the present invention is lesscostly to manufacture than conventional catheters, while meetingperformance requirements for use, including kink-resistance, curveretention, column strength and torque control.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described with reference to theaccompanying drawings where like numbers refer to like parts in severalviews and wherein:

FIG. 1 is a perspective view of a catheter of the present inventionhaving a tracking wire disposed therein.

FIG. 1A is a partial sectional view of the catheter of FIG. 1.

FIG. 1B is a sectional view of the catheter tracking wire of FIG. 1.

FIG. 2 is a perspective view showing an alternative embodiment of thecatheter of the present invention having an inner guide disposedtherein.

FIG. 2A is a partial sectional view showing the catheter of FIG. 2.

FIG. 2B is a partial perspective view showing an alternative embodimentof the catheter of FIG. 2.

FIG. 2C is a partial perspective view with a partial cutaway showing analternative embodiment of the catheter of FIG. 2.

FIG. 2D is a perspective view showing another alternative embodiment ofthe catheter of the present invention having an outer guide.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to an improved guide or diagnosticcatheter having a simple, braid-free design, which is capable ofperforming the functions of conventional diagnostic and guide catheters,while increasing lumen size back up support, radiopacity duringplacement, and dye control. The present invention provides aneconomically feasible diagnostic or guide catheter design which may beuniversally useable for most anatomical situations. The catheter of thepresent invention is less costly to manufacture than conventionalcatheters, while meeting performance requirements for use, includingkink resistance, curve retention, column strength and torque control.Although references throughout this specification may be specificallymade to either guide catheters or diagnostic catheters, references madeto one or the other are equally applicable to guide catheters anddiagnostic catheters, coronary, neuro, general peripheral, and anyvascular type catheters.

The focus of technology for guide and diagnostic catheters has centeredaround designs which provide kink resistance and torque response withina catheter tubular member. Kink resistance and torque response arenecessary so that manipulation of a proximal portion of the catheter isresponsively translated to the tip or distal end of the catheter tocurve and guide the catheter through the tortuous pathways of apatient's vascular system, to direct and position the distal tip of thecatheter near the coronary area receiving treatment while maintaining anopen lumen for the treatment procedure.

To achieve these performance characteristics, guide catheter designshave generally included a tubular member formed of three layers, whichinclude braiding or coiling integral to the catheter tube construction.The inner layer can be formed of a polytetrafluoroethylene or lubricouspolymer to decrease the coefficient of friction between the ballooncatheter or other device and the guide catheter. The middle layerconsists of braided or helically wrapped wires or filaments, for torquecontrol. The outer layer is generally a polymeric layer which gives thecatheter stable positioning within the patient's vascular system byproviding backup support during catheter procedures. The outer layer istypically formed of a polyethylene, polyurethane, polyether blockedamide or nylon-blend. Additionally, the outer layer usually isimpregnated with a radiopaque material, such as barium sulfate orbismuth subcarbonate, to allow for partial visualization of the cathetershaft during the catheter procedure.

Braided catheter designs are manufacturing intensive, requiringadditional costs, time, and manufacturing space. Additionally, braidedcatheter designs have performance limitations, including a larger wallthickness to accommodate the braided middle layer which limits availablelumen diameter for a given outside diameter.

The primary function of the braided middle layer, is to providesufficient torque and kink performance to the catheter body for properlypositioning the guide catheter within the coronary anatomy. Once thecatheter is positioned within the patient's vascular system, the needfor catheter kink and torque performance is no longer necessary.

The present invention provides a catheter (guide or diagnostic) whichcan be effectively positioned within the patient's coronary anatomy,without utilizing a braided middle layer. The guide catheter of thepresent invention includes the use of a tracking wire which may bepositioned into the selected coronary artery and allows the guidecatheter to be tracked over the tracking wire into the same coronaryartery.

FIG. 1 shows a perspective view of the braidless guide catheter assembly20 in accordance with the present invention. The catheter assembly 20includes a guide catheter 22 positioned over a tracking wire 24. Thetracking wire 24 provides the guide catheter 22 with the requiredperformance torque response and kink resistance necessary for guidingthe guide catheter 22 through the tortuous pathways of a patient'svascular system.

The guide catheter 22 includes a shaft 26 having a proximal end 28 and adistal end 30. A lumen 32, shown in FIG. 1A, extends longitudinallythrough the shaft from the proximal end 28 to the distal end 30.Operably connected to the proximal end 28 of the shaft 26 is a hubassembly 34, and connected to the distal end 30 of the shaft 26 is asoft tip 36.

The guide catheter 22 shaft 26 is formed of a single extruded polymerlayer 38 with or without a lubricous inner coating 40. It is recognizedthat shaft 26 may be formed by a co-extrusion process. In a preferredembodiment, layer 38 is formed of polyether blocked amide, polyethylene,polyurethane or a nylon blend. The layer 38 provides for stablepositioning within a patient's vascular system and backup support duringcatheter procedures. Preferably, the layer 38 is impregnated with aradiopaque material, such as barium sulfate or bismuth subcarbonate, toallow for partial visualization of the shaft 26 during catheterprocedures.

The lubricous inner coating 40 allows for near frictionless movement ofthe tracking wire 24 within the guide catheter lumen 32. In a preferredembodiment, the lubricous inner coating is a hydrophilic coating.Alternatively, the guide catheter 22 may include an inner layer formedof a lubricous polymer, such as polytetrafluoroethylene.

The absence of a braided layer within the guide catheter 22 allows theguide catheter 22 to have a larger inside diameter relative toconventional guide catheters of a given outside diameter which includethe braided middle layer. By maximizing the inside diameter relative tothe outside diameter, the guide catheter 22 is able to provide increasedperformance, including maximum dye flow and maximum catheter deliverysize.

The absence of the braided layer provides two alternative guide catheterconstructions. Preferably, the absence of the middle layer allows thecatheter design to have an internal diameter larger than is available inconventional guide catheters, while continuing to provide the sameamount of curve retention and backup support to the guide catheter. Inone embodiment, the internal diameter of the guide catheter 22 isapproximately 5 to 10 percent larger than the conventional braided guidecatheter having the same outside diameter with equivalent back-up andcurve retention performance. In the second alternative, additionalpolymer may be added to the shaft 26 layer 38 to increase the catheterwall volume. The additional polymer provides additional backup supportto the guide catheter 22 during catheter treatment procedures.

Referring to FIG. 1B, a cross-sectional view of the tracking wire 24 ofFIG. 1 is generally shown. The tracking wire 24 includes an elongateshaft 42 having a proximal end 44 and a distal end 46. Located at thedistal end 46 is a soft tip 48.

The shaft 42 includes an outer layer 50 formed over a core 52. The core52 extends from the proximal end 44 to the distal end 46, but does notextend through the soft tip 48. In a preferred embodiment, the core iswire, formed from stainless steel, a nickel titanium alloy (or Nitinol),or other material which provides sufficient strength and support. Theouter layer 50 is formed of polymer, preferably polyether blocked amide,polyethylene, polyurethane or nylon blend. The outer layer 50 can beimpregnated with a radiopaque material, such as barium sulfate orbismuth subcarbonate, for visualization of the shaft during catheterprocedures.

In a preferred embodiment, the specialty wire 24 is formed bypositioning a polymer sleeve over a stainless steel wire. The wire andpolymer sleeve are pulled through a heated die, forming the polymersleeve over the stainless steel wire. The outer layer 50 is then coatedwith a lubricous substance to aid in movement of the specialty wire 24through the guide catheter 22 lumen 32. In a preferred embodiment, thelubricous outer coating is a hydrophilic coating. Alternatively, thespecialty wire 24 may be formed by other extrusion or co-extrusionprocesses as known in the art.

The tracking wire 24 soft tip 48 is formed of soft polymer extendingbeyond the core 52. The tip 48 may be of a uniform outside diameter orpreferably, the tip 48 is tapered for safer ostial engagement.

The guide catheter 22 is preferably straight, however the guide catheter12 may be curved and shaped for access to specific coronary regions.With a straight guide catheter, the tracking wire 24 may be curved andshaped. With a curved tracking wire 24, the tracking wire 24 is advancedwithin a patient's vascular system until the soft tip 48 is engaged inthe ostium of the coronary artery to be treated. The guide catheter 22is then advanced over the specialty wire 24 until the guide cathetersoft tip 36 is similarly engaged in the ostium of the coronary arteryreceiving treatment.

During an angioplasty procedure, the femoral artery is enteredpercutaneously and a sheath is inserted into the artery to provideaccess to the patient's vascular system. The tracking wire 24 isinserted into the femoral artery through the introducer sheath andadvanced up to and over the aortic arch. The tracking wire 24 isadvanced and torqued until the tip 36 is engaged in the ostium of thecoronary artery receiving treatment. Next, the guide catheter 22 isinserted into the femoral artery through the introducer sheath, over thetracking wire 24.

The guide catheter 22 tracks the tracking wire 24 during advancementthrough the patient's vascular system. The guide catheter 22 is advancedover the tracking wire 24 until the distal end 30 passes over the aorticarch. As the guide catheter 22 is advanced over the tracking wire 24,through a patient's vascular system, the tracking wire 24 provides thekink and torque performance of conventional braided guide catheterdesigns.

With the soft tip 36 of the tracking wire 24 engaged in the ostium ofthe coronary receiving treatment, the guide catheter is advanced overthe tracking wire until the guide catheter soft tip 36 is similarlyengaged in the ostium of the coronary receiving treatment. Once theguide catheter 22 is positioned within the ostium of the coronary arteryreceiving treatment, the need for kink and torque performance is nolonger necessary and the tracking wire 24 may be removed.

Once the tracking wire 24 is removed, the guide catheter 22, including alarger lumen 32, is able to provide the physician with increased dyedelivery, and a larger lumen for accommodating a larger balloondilatation catheter.

In a preferred embodiment, the tracking wire 24 has an outside diameterof 0.038″ for use with 5F, 6F and 7F catheters and 0.063″ for use with8F, 9F and 10F catheters. It is also recognized that the tracking wire24 may be used by the physician for guide catheter exchange proceduresfor exchanging to a larger guide catheter. The tracking wire 24 wouldprovide stability and support during removal and exchange of the guidecatheter. Preferably, the tracking wire 24 would include a magneticallyresponsive/active section at its proximal end, which can be similar tothe magnetic sections disclosed in the catheter exchange devices inapplication Ser. Nos. 08/048,492 and 07/929,083. The tracking wire 24would then be used for guide catheter exchange procedures, which can besimilar to those disclosed in application Ser. No. 08/397,578 for usewith magnetic exchange devices application Ser. Nos. 07/929,083;08/048,492; and 08/397,578 are herein incorporated by reference.

Referring to FIG. 2, another embodiment of the guide catheter assembly20 of the present invention is generally shown. The catheter assembly 20includes a guide catheter 22 and an inner guide member 60. Theconstruction of the guide catheter 22 can be similar to the constructionof the guide catheter 22 shown and described previously in FIG. 1. Thecatheter assembly 20 with the inner guide 60 provides the physician witha guide catheter that has a simple, braid-free catheter design, which iscapable of performing the functions of conventional guide catheters.

Referring to FIGS. 2, 2A and 2B, the inner guide 60 generally includes ashaft 62 having a proximal end 64 and a distal end 66. A lumen 68extends longitudinally through the shaft 62 from the proximal end 64 tothe distal end 66. Operably connected to the proximal end 64 of theshaft 62 is a hub assembly 70, for connection to catheterizationequipment, including the hub assembly 34 of guide catheter 22. Connectedto the distal end 66 of the shaft 62 is a soft tip 72, which may betapered.

The inner guide 60 is formed using extrusion processes which can besimilar to the formation of the guide catheter 22. In a preferredembodiment, the inner guide 60 includes a single layer 74 formed ofextruded polymer, preferably fiber filled with liquid crystal polymer(LCP), glass fiber, Kevlar fiber, carbon fiber, or other similar fiber.Alternatively, the inner guide 60 may be multilayered.

The single layer 74 is formed of a polymeric material, such as polyetherblocked amide, polyethylene, polyurethane, or a nylon blend, for stablepositioning, kink-resistance, and torque control of the guide catheter22.

Due to the relatively thin walls of guide catheter 22 and inner guide60, the inner guide 60 may also be impregnated with radiopaque materialssuch as barium sulfate, or bismuth subcarbonate for visualization of theshaft during catheterization procedures. In the preferred embodiment,the inner guide 60 single layer 74 is formed of a polyether blockedamide or PEBA impregnated with 20-60 percent radiopaque materials havinga relatively high durometer.

The outside diameter of the inner guide 60 is sized for slidableinsertion within the lumen of the guide catheter 22. The outsidediameter of the inner guide 60 is of sufficient size to provide support,torqueability, and kink-resistance to guide catheter 22 for positioningguide catheter 27 within the patient's coronary anatomy. The insidediameter of the inner guide 60 lumen 68 is sized to accommodate standardcatheter procedure guide wires. In the preferred embodiment, the insidediameter of inner guide 60 lumen 68 is between 0.038 and 0.040 inches toaccommodate 0.035 inch guide wires.

When the inner guide 60 is inserted within the guide catheter 22 lumen32, the inner guide hub assembly 70 connects to the guide catheter 22hub assembly 34. By locking the inner guide 60 hub assembly 70 to theguide catheter 22 hub assembly 34, the inner guide 60 may be used toposition and torque the guide catheter 22 into the desired location inthe coronary anatomy. The inner guide 60 provides support,kink-resistance, and torquability to the braidless guide catheter 22during introduction and positioning of the guide catheter within thepatient's vascular system. The inner guide 60 may or may not extendbeyond the distal end 30 of guide catheter 22.

With the inner guide 60 hub assembly 70 locked to the guide catheter 22hub assembly 34, dye may be injected into the patient's vascular systemthrough the inner guide 60 lumen 68. By injecting dye through the innerguide lumen 68, the amount of dye released into the patient's system maybe easily controlled, especially where the inner guide 60 is positionedwithin a larger size catheter. In the preferred embodiment, the outsidediameter of the inner guide 60 varies relative to the size of guidecatheter 22, but the inside diameter of inner guide is constant,preferably approximately 0.038 inches. A Y-adaptor and manifold assemblymay be attached to the catheter assembly 20 including the guide catheter22 and inner guide 60 for contrast dye and flush delivery and pressuremonitoring. Additionally, by locking the inner guide hub assembly 70with the catheter hub assembly 34, the catheter assembly 20 acts as ananti-bleeding device for preventing back bleeding through the guidecatheter 22.

In use, the femoral artery is entered percutaneously and a sheath isinserted into the artery to provide access for the catheter assembly 20to the patient's vascular system. The guide wire, preferably a 0.035inch wire, is inserted through the femoral sheath into the patient'svascular system and advanced up and over the aortic arch. The innerguide 60 is inserted into the guide catheter 22, with hub assembly 70locked to hub assembly 34, to form catheter assembly 20. The catheterassembly 20 is introduced over the guide wire through the femoralintroducer sheath and advanced up to the aortic arch. As the catheterassembly 20 is advanced up and over the aortic arch, the inner guide 60provides support, kink-resistance, and torquability to the braidlessguide catheter 22.

After advancing the catheter assembly 20 over the aortic arch, the guidewire can then be removed. A Y-adaptor and manifold assembly are attachedto the catheter assembly 20 for injection of dye contrast, flushdelivery, and pressure monitoring. The contrast media allows thephysician to locate the ostium for seating the guide catheter 22.

The catheter assembly 20 is now advanced and torqued until it is engagedin the ostium of the vessel which is to receive treatment. Once theguide catheter 22 is engaged within the desired ostium, the inner guide60 may be removed. The luer attached to the inner guide hub assembly 70and the catheter hub assembly 34 is unlocked, and the inner guide hubassembly 70 is disconnected from the catheter hub assembly 34. The innerguide 60 is pulled out and removed.

The inner guide 60 provides torquability and kink-resistance to theguide catheter 22 for positioning the guide catheter 22 within thepatient's coronary anatomy. Once the guide catheter 22 is correctlypositioned within the patient's coronary system, the need forkink-resistance and torquability is no longer necessary, and the innerguide 60 may be removed. After removal of the inner guide 60, thephysician may proceed with treatment of the diseased area, such asthrough the use of a balloon dilatation system, as the physician wouldwhen using a conventional guide catheter.

In a preferred embodiment, the inner guide 60 may be curved or shaped,and guide catheter 22 straight. The curved inner guide 60 would giveshape to the catheter assembly 20 for accessing specific areas withinthe patient's coronary anatomy. Alternatively, it is recognized that thesame function may be accomplished by providing a straight inner guide 60with a curved or shaped guide catheter 22.

In one preferred embodiment for smaller catheter sizes, such as 5F, 6F,or 7F, the inner guide 60 is curved or shaped, and the guide catheter 22is curveless or straight. Referring to FIG. 2B, the inner guide 60distal end 66 extends beyond the guide catheter 22 distal end 30. Withthe catheter assembly 20 advanced over the aortic arch, the inner guide60 distal end 66 (and specifically tip 72) is engaged in the ostium ofthe vessel to receive treatment. The guide catheter 22 is tracked overthe inner guide 60 until the distal end 30 is similarly engaged in theostium to receive treatment.

The inner guide, which is curved or shaped, is then removed. Thecurveless guide catheter 22 is positioned within the ostium of thecoronary artery receiving treatment. The curveless guide catheter 22provides better support to the treatment system while being lesstraumatic to the patient's vascular system than a shaped cathetersystem, which would induce preformed stresses within the vessels due toits curved structure.

In another preferred embodiment for larger catheter sizes, such as 8F,9F and 10F, the inner guide 60 is curveless and the guide catheter 22 iscurved or shaped. Referring to FIG. 2C, the guide catheter 22 distal end30 extends beyond the inner guide 60 distal end 66. The inner guide 60provides torqueability and kink resistance to guide catheter 22 forpositioning the guide catheter 22 within the patient's coronary anatomy.Once the catheter assembly 20 is advanced over the aortic arch, thecatheter assembly 20 is torqued and advanced until the guide catheter 22distal end 30 is engaged in the ostium of the vessel to receivetreatment.

Once the guide catheter 22 is correctly positioned within the patient'scoronary system, the need for kink resistance and torqueability is nolonger necessary, and the inner guide 60 may be removed. After removalof the inner guide 60, the physician may proceed with treatment of thediseased area, such as through the use of a balloon dilatation system,as the physician would when using a conventional guide catheter.

Referring to FIG. 2D, yet another embodiment of the present invention isshown. The catheter assembly 20 includes a guide catheter 22 and anouter guide 80. The outer guide 80 can be similar in construction to theinner guide 60 which was previously detailed herein. Similarly, theouter guide 80 provides the same function as previously described innerguide 60, in that it provides torqueability and kink resistance to theguide catheter 22 for positioning the guide catheter 22 within thepatient's coronary anatomy. Once the guide catheter 22 is correctlypositioned within the patient's coronary system, the need for kinkresistance and torqueability is no longer necessary, and the outer guide80 may be removed. After removal of the outer guide 80, the physicianmay proceed with treatment of the diseased area, such as through the useof a balloon dilatation system, as the physician would when using aconventional guide catheter.

The outer guide 80 may be curved or shaped, and the guide catheter 22curveless or straight. The curved outer guide 80 would give shape to thecatheter assembly 20 for accessing specific areas within the patient'scoronary anatomy. Alternatively, it is recognized that similar functionsmay be accomplished by providing a straight or curveless outer guide 80with a curved or shaped guide catheter 22. The guide catheter 22 may ormay not extend beyond a distal end 82 of the outer guide 80. In use, theouter guide 80 functions similar to inner guide 60 duringcatheterization procedures. The femoral artery is enteredpercutaneously, and a sheath is inserted into the artery to provideaccess for the catheter assembly 20 to the patient's vascular system. Aguide wire is inserted through the femoral sheath into the patient'svascular system and advanced up over the aortic arch. The outer guide 80is positioned over the guide catheter 22 to form catheter assembly 20.The outer guide 80 and guide catheter 22 may be secured together attheir proximal ends using a hub assembly similar to that previouslydescribed herein, or they may be secured together by other means, suchas the use of magnetically active segments which can be similar to thosedisclosed in U.S. application Ser. Nos. 07/929,083; 08/048,429; and08/397,578 for use with magnetic devices. U.S. application Ser. Nos.07/929,083; 08/048,429; and 08/397,578 have been previously incorporatedinto this application by reference.

The catheter assembly 20 is introduced over the guide wire through thefemoral introducer sheath and advanced up to and over the aortic arch.As the catheter assembly 20 is advanced up and over the aortic arch, theouter guide 80 provides support, kink resistance, and torqueability tothe braidless guide catheter 22.

After advancing the catheter assembly 20 over the aortic arch, the guidewire can be removed. A Y-adapter and manifold assembly may be attachedto the catheter assembly 20 for injection of die contrast, flushdelivery, and pressure monitoring. The contrast media allows thephysician to locate the ostium for seating the guide catheter 22.

The catheter assembly 20 is now advanced and torqued until it is engagedin the ostium of the vessel which is to receive treatment. The guidecatheter 22 distal end 36 may be engaged in the ostium. Alternatively,if the outer guide 80 extends beyond the guide catheter 22, the outerguide 80 distal end 82 may be engaged within the coronary ostium, andthen the guide catheter 22 distal end 30 may be advanced and similarlyengaged in the ostium of the coronary to receive treatment. Once theguide catheter 22 is correctly positioned within the patient's coronarysystem, the need for kink resistance and torqueability is no longernecessary, and the outer guide 80 may be removed. After removal of theouter guide 80, the physician may proceed with treatment of the diseasedarea, such as through the use of a balloon dilatation system, as thephysician when using a conventional guide catheter.

The guide catheter assembly 20 of the present invention, would providefor increased performance during diagnostic procedures. The dimensionsof the diagnostic catheter could be scaled appropriately and constructedto withstand adequate burst pressures for high pressure dye deliverytypical of diagnostic procedures. The present invention would allow thephysician to use diagnostic catheter shapes for visualizing variousareas of the coronary system, without having to remove the diagnosticcatheter from the patient's body. The time saving procedure using thepresent invention also results in less patient exposure to fluoroscopy.

The present invention provides a catheter which can be effectivelypositioned within the patient's coronary anatomy, without utilizing abraided middle layer. The absence of a braided layer within the guidecatheter allows the guide catheter to have a lumen with a larger insidediameter relative to conventional guide catheters of a given outsidediameter formed of braided construction. By maximizing the insidediameter relative to the outside, the guide catheter is able to provideincreased performance, including maximum dye flow and maximum catheterdelivery size. Additionally, the guide catheter of the present inventionprovides equivalent back-up and curve retention performance to that ofconventional guide catheters.

It will be understood, that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, material, and arrangement of parts without exceeding thescope of the invention. Accordingly, the scope of the invention is asdefined within the language of the appended claims.

What is claimed is:
 1. A catheter assembly for use in catheterprocedures, comprising: a guide catheter comprising a braidless shaft,wherein the shaft comprises a proximal end, a distal end, and a lumenextending longitudinally therethrough, the guide catheter sized toextend within the vasculature from an entry location in the femoralartery to a blood vessel in the upper abdomen of a human patient; aninner guide member comprising an elongate shaft, wherein the elongateshaft comprises a proximal end, a distal end, and a lumen extendinglongitudinally therethrough; and the inner guide member is adapted forinsertion within the lumen of the guide catheter, thereby supporting theguide catheter shaft during catheter placement.
 2. The catheter assemblyin accordance with claim 1, wherein the inner guide member furthercomprises a non-metallic coating.
 3. The catheter assembly in accordancewith claim 1, wherein the guide catheter further comprises a soft tipdisposed at the distal end thereof.
 4. The catheter assembly inaccordance with claim 3, wherein the soft tip is tapered.
 5. Thecatheter assembly in accordance with claim 1, wherein the inner guidemember is curved.
 6. The catheter assembly in accordance with claim 1,wherein the guide catheter is curved.
 7. The catheter assembly inaccordance with claim 1, wherein the proximal end of the guide cathetershaft is adapted to connect to a hub assembly.
 8. A catheter assemblyfor use in catheter procedures, comprising: a guide catheter comprisinga braidless shaft, wherein the shaft comprises a proximal end, a distalend, and a lumen extending longitudinally therethrough, the guidecatheter sized to extend within the vasculature from an entry locationin the femoral artery to a blood vessel in the upper abdomen of a humanpatient; wherein the guide catheter shaft comprises a polymer layer; aninner guide member comprising an elongate shaft, wherein the elongateshaft comprises a proximal end, a distal end, and a lumen extendinglongitudinally therethrough; and the inner guide member is adapted forinsertion within the lumen of the guide catheter, thereby supporting theguide catheter shaft during catheter placement.
 9. The catheter assemblyin accordance with claim 8, wherein the inner guide member furthercomprises a non-metallic coating.
 10. The catheter assembly inaccordance with claim 8, wherein the guide catheter further comprises asoft tip disposed at the distal end thereof.
 11. The catheter assemblyin accordance with claim 10, wherein the soft tip is tapered.
 12. Thecatheter assembly in accordance with claim 8, wherein the inner guidemember is curved.
 13. The catheter assembly in accordance with claim 8,wherein the guide catheter is curved.
 14. The catheter assembly inaccordance with claim 8, wherein the proximal end of the guide cathetershaft is adapted to connect to a hub assembly.
 15. A catheter assemblyfor use in catheter procedures, comprising: a guide catheter comprisinga braidless shaft, wherein the shaft comprises a proximal end, a distalend, and a lumen extending longitudinally therethrough, the guidecatheter sized to extend within the vasculature from an entry locationin the femoral artery to a blood vessel in the upper abdomen of a humanpatient; wherein the shaft comprises a polymer layer and a lubricousinner coating; an inner guide member comprising an elongate shaft,wherein the elongate shaft comprises a proximal end, a distal end, and alumen extending longitudinally therethrough; and the inner guide memberis adapted for insertion within the lumen of the guide catheter, therebysupporting the guide catheter shaft during catheter placement, whereinthe lubricous inner coating allows for near frictionless movement of theinner guide member within the guide catheter lumen.
 16. The catheterassembly in accordance with claim 15, wherein the inner guide memberfurther comprises a non-metallic coating.
 17. The catheter assembly inaccordance with claim 15, wherein the guide catheter further comprises asoft tip disposed at the distal end thereof.
 18. The catheter assemblyin accordance with claim 17, wherein the soft tip is tapered.
 19. Thecatheter assembly in accordance with claim 15, wherein the inner guidemember is curved.
 20. The catheter assembly in accordance with claim 15,wherein the guide catheter is curved.
 21. The catheter assembly inaccordance with claim 15, wherein the proximal end of the guide cathetershaft is adapted to connect to a hub assembly.
 22. A method ofsupporting a catheter for positioning the catheter within a patient'svascular system, the method comprising: providing a catheter assembly,the catheter assembly including a guide catheter comprising a shaft,wherein the shaft comprises a proximal end, a distal end, and a lumenextending longitudinally therethrough, wherein the shaft comprises apolymer layer and a lubricous inner coating; an inner guide membercomprising an elongate shaft, wherein the elongate shaft comprises aproximal end, a distal end, and a lumen extending longitudinallytherethrough; and the inner guide member is adapted for insertion withinthe lumen of the guide catheter, thereby supporting the guide cathetershaft during catheter placement, wherein the lubricous inner coatingallows for near frictionless movement of the inner guide member withinthe guide catheter lumen; inserting the inner guide member within thepatient's vascular system; advancing the guide catheter over the innerguide member, the inner guide member being of sufficient outsidediameter for continual slidable contact with the guide catheter, therebysupporting and guiding the guide catheter; and positioning the distalend of the guide catheter within the patient's vascular system.
 23. Themethod of claim 22, further comprising the step of: positioning thedistal end of the inner guide member within an ostium of the patient'svascular.
 24. The method of claim 23, further comprising the step of:advancing the guide catheter over the inner guide member until thedistal end of the guide catheter is positioned within the ostium. 25.The method of claim 22, further comprising the step of: removing theinner guide member.
 26. The method of claim 22, further comprising thesteps of: inserting the inner guide member through a femoral introducersheath into the patient's vascular system; and inserting the guidecatheter through the femoral introducer sheath into the patient'svascular system.